Machine for welding



NOV. 13, 194-5 MARTINDELL 2,388,754

MACHINE FOR WELDING Filed July 10, 1942 3 Sheets-Sheet 3 II II INVENTOR.f"? MnRr/NDELL Patented Nov. 13, 1945 MACHINE FOR WELDING FrankMartlndell, Western Springs,

to Western Electric Company,

111., assignor Incorporated,

New York, N. Y., a corporation or New York Application July 10, 1942,Serial No. 450,409

v 8 Claims. This invention relates to a machine for welding,

I and its object is to provide an improved machine for accurately andeconomically welding contacts to switch springs or other elements ofelectrical apparatus.

In accordance with one embodiment of the invention, a. machine forelectrically welding contacts to switch springs is provided, in which anend portion of an intermittently advanced continuous strip of contactmetal is clamped to the switch spring by the welding electrodes, afterwhich the end portion of the contact strip is severed from the strip andthereafter welded to the switch spring, after first retracting thecontinuous strip of contact metal from the severed portion to preventdiversion of the welding current through the continuous strip.

Other features and advantages of the invention will become apparent fromthe following detailed description taken in conjunction with theaccompanying drawings, in which:

Fig. l. is a fragmentary side view, partly in section, of a contactweldin machine embodying the features of this invention;

Figs. 2 and 3 are enlarged vertical sectional views of portions of themachine shown in Fig. 1;

Fig. 4 is an enlarged vertical section of the contact strip feedingchuck;

Fig. 5 is a vertical section on line 5-5 of Fig. l;

Fig. 6 is a horizontal section on line of Figs. 3' and S are per reviews of the con tact strip gri ping a jaws;

9 is an enla d fragmentary section on line d ll of Fig. 4

Fig. 10 is an enlarged fragmentary vertical sec=- tion similar to thelower portion of Fig. 2, but showing the upper electrode and the cutterin their operated positions;

Fig. 11 is an enlarged fragmentary section on line ll--li of Fig. 10;

Fig. 12 is a fragmentary section on line l2-l2 of Fig. l, and

Fig. 13 is an enlarged fragmentary horizontal section on line III-l3 ofFig. 1.

Referring now to the drawings, and particularly to Fig. 1, the weldingmachine illustrated therein comprise a cylindrical lower weldingelectrode and a circular upper welding electrode 2i, the latter beingvertically movable toward and away from the lower electrode. The upperelectrode is clamped to an upper electrode supporting head 22 by meansof a clamping block 23 (Fig. 2) and a cooperating clamping screw 24threaded into an internally threaded tubular shank 25 of the clampingblock. The block 23 is formed with a vertical channel 26 for slidablyreceiving a vertically reciprocable chisel-like cutter 28, the functionof which is to sever the contacts from a continuous strip or contactmaterial in the manner hereinafter described,

The upper electrode supporting head 22 is attached to a crosshead 29 atthe lower end of a vertical bar 30, which ismounted for verticalmovement in a vertical sleeve 32 supported in a bracket 3i attached to agear housing 33 (Fig. 1). This gear housing is secured to the upper endof a tubular post 35, which is mounted for vertical adjustment in atubular bracket 36 attached to a base plate 327 of the machine.

An upper electrode operating lever 49 is pivoted intermediate its endupon a horizontal pivot pin ii in the bracket 3i. One end of this leveris adapted to engage the underside of a collar d2 fired to the upperelectrode supporting bar 30. lhe opposite end of the lever is equippedwith a roller 44 for engaging a cam (l5 fixed to a cam shaft 56journalled in the gear housing. The cam operates through lever 30 toelevate or retract the upper electrode against the opposing force of acoil spring 48 (Fig. 2) on the upper end of electrode supporting her3i). This spring is compressed between the upper side of collar 52 and aspring housing 39, the latter being vertically adjustable in ahorizontal arm at of bracket 35 to adjust the tension. of the spring.

Th cam shaft 5' driven through gears cal shaft h. turn, y horithe shaftjournalled underne plate J? of the machine. The gear In I that for eachcomplete revolution of th shaft earn shaft til also makes one completerevolution. The lower electrode 23 is attached to the upper end of a.vertical shaft 56 (Fig. 1) which is ro-= tatably journalled in a tubularbearing mounted for vertical adjustment in the base plate it. As shownin Fig. 1, the tubular bearing 52 is threaded in a flanged tubularbracket 58 attached to the base plate, so that by turning the bearing inthe bracket, the hearing may be elevated or lowered to adjust theposition of the lower elec-= trode with respect to the upper electrode.

Mechanism is provided for indexing the lower electrode after eachwelding operation to present a cool portion of the electrode for eachwelding operation. This mechanism comprises a driven clutch member 60(Figs. 1 and 13) attached to the lower electrode supporting shaft, and adriving clutch member 5| which surrounds the driven clutch memberrotates around the clutch rollers 62. For imparting the requiredintermittent clockwise movement to the driving clutch member, there isprovided on the driving shaft 55 a driving disk 66 having a drivingfinger 6'? attached thereto and extending radially therefrom. Thisdriving finger cooperates with a peripheral projection Ed on the drivingdisk to impart thereto a predetermined clockwise movement during eachrevolution of th driving shaft. This movement of the driving clutchmember is transmitted through the clutch rollers 62 to the driven clutchmember fill, whereby the lower electrode is rotated sufiiciently topresent a cool portion thereof for the next welding operation. Aftereach indexing operation, the driving finger 6? slides by the projection58 on the driving clutch member, whereupon the torsion spring -65returns the driving clutch member to its original position.

A cylindrical rod ID (Fig. 1) is mounted in a vertical position abovethe upper electrode supporting bar 3% and in axial alignment therewith.The lower end of this rod is fixed in a horizontal arm H of bracket 3!and its upper end extends through a bearing block 12 fixed to the gearhousing 33. A bracket Hi is mounted on the upper end of rod it and asimilar bracket 15 is mounted on the upper electrode guiding sleeve 32.To these two brackets there is attached a vertical plate 11 upon whichis mounted th mechanism for feeding a continuous strip 80 of contactmetal from a supply spool (not shown) to the welding electrodes.

The contact strip feeding mechanism comprises a tubular spindle 82(Figs. 2 and 3), which is slidable in a vertical sleeve Bl. The sleeveBI is vertically slidable in guide blocks 83 and 8 5 secured to themounting plate ll. The spindle 82 has a chuckv 85 attached to its lowerend. This chuck comprises a block 8% having a transverse slot 89 (Fig.4) within which a pair of cooperating clamping jaws 81 and 88 aremounted, one of the jaws, 81, being horizontally slidable toward andaway from the other jaw. The opposed faces of the two clamping jaws aregrooved to provide a vertical guide passage 98 therebetween conformingto the cross section of the contact strip 80. When the clamping jaws areopened, they are free to slide along the contact strip as the chuck iselevated with the spindle 82 in the manner hereinafter described.

Clamped to the sleeve 8| above the bearing block 813 is a collar 9! towhich the upper end of a vertical chuck actuating link 92 is pivotallyconnected. This link is pivotally connected at its lower end to theouter ends of two spaced pairs of toggle links, each pair comprising ashort link 93 and a long link 94. The short links 93 are pivotallyconnected at their inner ends to the chuck block 86, while the longlinks 94 are pivotally connected to a pin 95 disposed in a slot 96 i themovable chuck jaw 81. The construction is such that when the togglelinks are collapsed by downward movement of the toggle operating link92, the movable chuck jaw 81 is free to move away from the other jaw 88sufiiciently to permit the two jaws to slide along the contact strip,but when the toggle links are straightened by upward movement of thetoggle operating link, the movable jaw is moved toward the other law sothat the contact strip is firmly gripped between the two laws as shownin Figs. 2 and 4. A cover plate 98 is provided over the slot 89 in thechuck block for limiting the opening movement of the movable jaw of thechuck.

As mentioned above, the chuck closing link 92 I is attached at its upperend to the collar 96 which is fixed to the sleeve 8i. Thus, the link 92is constrained to move with this sleeve which is urged upwardly on thefeed spindle 82 by a coil spring Wt interposed between an adjustableextension E02 on the upper end of the sleeve and the upper end of aspacer sleeve it above the chuck block 86. By urging sleeve 8| upwardly,the spring I00 tends to straighten the toggle links 93 and. 9d andthereby close the chuck jaws on the contact strip. For moving the chuckoperating sleeve 8| downwardly against the opposing force of the springto release the chuck jaws from the contact strip, there is providedarock lever IM which is pivoted intermediate its ends on the mountingplate l1.

One end of this lever rests on a collar I05. This collar is slidable onthe vertical rod 10 and rests on one end of a cam lever I06 which ispivoted intermediate its ends on the bracket 35. At its opposite end,the cam lever N36 has a depending leg Nil which carrie a roller I08adapted to ride on a cam I09 fixed to the cam shaft 46. This cam isdesigned to rock lever [0d so as to depress chuck operating sleeve 8iand thereby open the chuck jaws at the proper time during each operatingcycle of the machine. A handl H0 is provided on the rock. lever lot formanually opening the chuck jaws when necessary; for example, whenadjusting or setting up the machine.

The upper end of the contact strip feeding spindle 82 is slidable in aspring plunger sleeve H2 (Fig. 3) which, in turn, is slidable in anadjustable bushing H3 threaded in a supporting block I Hi attached tothe mounting plate 11. The plunger sleeve H2 has a flange H5 at itslower end which is pressed upwardly by a spring H6 against one end of arock lever ill which is pivoted intermediate its ends on the mountingplate 'l'l (Fig. 1). i The opposite end of this rock lever rests on acollar I I8 which is slidable on the vertical rod in and rests on oneend of a cam lever lZll. This cam lever is pivoted intermediate its endson the bracket 3| and has a depending leg l2i which carries a roller H22adapted to ride on a cam I23 fixed to the cam shaft Q6. The cam isdesigned to rock the lever lli so as to depress the plunger sleeve H2 atthe proper time during each operating cycle of the machine. Interposedbetween the plunger sleeve and a collar 525 fixed to the strip feedingspindle is a spring I26 through which the downward movement of theplunger sleeve is transmitted to the strip feeding spindle, therebyadvancing the previously gripped contact strip downwardly through aguide quill I28 which directs the contact strip toward the weldingelectrodes.

A. stop sleeve I30 is threaded on the upper end of the strip feedingspindle 82 and is adapted to engage the flanged upper end of bushing M3to limit the downward movement of the feed spindle. By simply turningthis stop sleeve, it may be adjusted longitudinally of the feed spindleto vary the extent of downward movement of the feed spindle, whereby thelength of contact strip advanced during each feeding cycle ispredetermined. It will be understood that after the feed spindle hasbeen depressed to its lowermost position against stop bushing II3,further downward movement of the plunger sleeve H2 is taken up by thesprin I 26.

The guide quill I28 is composed of two curved plates I32 and I33attached to the mounting plate I1. The opposed surfaces of these platesare grooved to provide a contact strip guiding passage I35, the lowerendof which curves toward the welding electrodes, as best shown in Figs.2 and 10. Plate I 32 is formed at its lower end with a horizontalextension I36 which projects beyond the lower end of plate I33 and isprovided on its underside with a contact strip guiding groove I38 (Fig.10) in alignment with the discharge end oi. the guide passage I35. Thefree end portion of the contact strip is yieldably held in the grooveI38 by means of a fiat spring I39 attached at one end to the plate I33.The free end of this spring is bent over and is provided with anaperture I40 for directing the end of the contact strip into a positionimmediately below the upper electrode, as shown in Fig. 2.

As mentioned above, the vertically reciprocable chisel-like cutter 28,which is mounted on the face of the upper electrode 2|, serves to severcontacts from the end of the continuous strip of contact metal. Thiscutter is pivotally connected at I42 to one end of a lever I43 which ispivoted intermediate its ends on the mounting'plate I1. The opposite endof lever I43 is connected by a adjustable link I44 (Fig. 1) to one endof a rock lever I45 which is pivoted intermediate its ends on a bracket$46 attached to block 83. The opposite end of this rock lever ispivotally connected to a collar I48 which is slidable on the rod I70. Aspring I48 urges the collar upwardly against one end of a cam lever I50which is pivoted intermediate its ends on the bracket 3!. The oppositeend of this cam lever carries a roller il adapted to ride on a cam I52on cam shaft 45. The cam is designed to actuate the interconnectedlevers and links so as to operate the cutter 28 at the proper timeduring each cycle of operation of the machine.

In the operation of the machine, a switch spring I60, on which a contactis to be welded, is placed by the operator upon a suitable fixture I6I,which positions the switch spring so that one end thereof extends abovethe lower welding electrode 20, as shown in Figs. 1 and 2. An operatingcycle of the machine is then started by the operator by operativelyconnecting the shaft 55 with a suitable driving means (none shown) whichincludes conventional mechanism for stopping the machine automaticallyupon the completion of an operating cycle. The details of the drivingmechanism and the means for supplying the welding current to the weldingelectrodes have been omitted, since they form no part of the presentinvention, and a detailed disclosure thereof is believed unnecessary toa complete understanding of the present invention. It is believedsufiicient to state herein that during each operating cycle of themachine, shaft 55 and cam shaft 48 each make one, and only one, completerevolution and then stop automatically, and

'at the end of each operating cycle, the operated parts of the machinecome to rest in the positions in which they are shown in Fi 1 .At thebeginning of each operating cycle of the machine, the finger 61 ondriving disk 88 indexes the lower electrode 20 to move a cool por-- tionthereof to the welding position, and the upper electrode elevating cam45 permits spring 48 to move upper electrode 2| downwardly into clampingengagement with the previously advanced end portion a of the contactstrip 80 projecting from the lower end of the guide plate I32, wherebythe end portion of the contact strip and the end portion of the switchspring are clamped together between the upper and lower electrodes.Simultaneously therewith, the chuck opening cam I09 operates throughlevers I08 and I04 to depress chuck operating sleeve 8| on feed spindle82. This downward movement of the chuck operating sleeve is transmittedthrough the link 92 (Fig. '2) to collapse the toggle links 93 and 94 andthereby release the chuck jaws 81 and 88 from gripping engagement withthe contact strip. The feed spindle 82 is then elevated to anintermediate position by the spring pressed sleeve II2 (Fig. 3) underthe control of the cam I23 (Fig. 1), which has a dwell portion I23a forholding the feed spindle in the intermediate position while thepreviously clamped end portion 80a of the contact strip is severed by adownward movement of the chisel-like cutter 28 under the control of cami52.

The chuck opening cam Hi9 (Fig. 1) is designed to permit spring i00(Figs. 2 and 3) to shift chuck operating sleeve 8i upwardly on the feedspindle and thereby close the chuck jaws into gripping engagement withthe contact strip just prior to the cutting operation. Immediately afterthe cutting operation, the feed spindle 82 is elevated to its uppermostposition by the spring pressed sleeve 2 under the control of the cami23. whereby the previously gripped contact strip 30 is retracted fromthe previously severed end portion 80a thereof, so as to prevent thediversion of welding current through the continuous strip of contactmetal during the welding operation, which is timed by suitable means(none shown) to take place immediately after the retraction of thecontinuous contactstrip from the severed end portion thereof.

After the severed end portion of the contact strip has been welded tothe switch spring, the upper electrode W is elevated or'retracted by thecam 45 and simultaneously therewith the contact strip feeding spindle 82is moved downwardly by cam H23 to advance a fresh end portion of thecontact strip into position below the retracted upper electrode, thuscompleting an operating cycle of the machine, which may be repeated byagain connecting the shaft 55 with the driving means.

It is to be understood that the invention is not limited to theparticular embodiments thereof herein illustrated and described, but iscapable of other applications within the scope of the appended claims.

What is claimed is:

1. In a machine for welding a piece of metal to an article, meanscomprising a. movable memher for clamping a portion of a strip of metalto the article, and a reciprocatory cutter mounted on said member forsevering the clamped portion of the metal strip from the remainingstrip.

2. In a machine for welding a piece of contact metal to an article,means for clamping an end portion of a continuous strip of contact metalto a surface of the article, and a reciprocatory cutter adapted tooperate against said surface of the article to sever the clamped endportion of contact metal from the continuous strip.

of contact metal to a switch spring, means for clamping an end portionof a continuous strip of contact metal to the switch spring, means forsevering the clamped end portion from the continuous strip, and meansfor retracting the continuous strip from the clamped severed portion.

5. In a machine for welding a contact to a switch spring, a pair ofwelding electrodes, one of which is movable relative to the other, meansfor advancing a continuous strip of contact metal toward saidelectrodes, means for moving the movable electrode toward the otherelectrode to clamp an end portion of the continuous strip to a switchspring interposed between said electrodes, and a reciprocatory cuttermounted on the movable electrode for severing the clamped end portion ofthe contact metal from the continuous strip.

6. In a machine for welding a contact to a switch spring, a pair ofwelding electrodes, one of which is movable relative to the other, meansfor advancing a continuous strip of contact metal toward saidelectrodes, means for moving the movable electrode toward the otherelectrode to clamp an end portion of the continuous strip to a switchspring interposed between said electrodes, means movably mounted on themovable electrode for severing the clamped end portion from thecontinuous strip, means for thereafter retracting the continuous strip,means for energizing the welding electrodes to weld the severed endportion of the continuous strip to a switch spring, and means foroperating said energizing means and retracting means in timed relation.

'7. In a machine for welding a contact to a switch spring, a pair ofwelding electrodes, one of which is movable relative to the other, meansfor intermittently advancing a continuous strip of contact metal toinsert an end portion thereof between said electrodes, means for movingthe movable electrode toward the other electrode to clamp the said endportion of the metal strip to a switch spring interposed between saidelectrodes, means for thereafter severing the said end portion from thecontinuous strip, means for re,- tracting the continuous strip from saidsevered end portion to prevent diversion of welding current through saidcontinuous strip, and means comprising a shaft and a series of cams onsaid shaft for controlling the operation of the several aforementionedmeans.

8. In a machine for welding a contact to a switch spring a pair ofwelding electrodes, one of which is movable relative to the other, areciprocatory feed spindle having a releasable chuck for intermittentlyadvancing a continuous strip of contact metal to insert an end portionthereof between said electrodes, means for moving the movable electrodetoward the other electrode to clamp the said end portion of the metalstrip to a switch spring inserted between said electrodes, means forreleasing the chuck, means for retracting the feed spindle with itschuck released to an intermediate position while the said end portion ofthe metal strip is clamped to the switch spring, means for thereaftersevering the said end portion from the continuous strip, and means forthereafter operating the feed spindle to retract the continuous stripfrom the severed end portion thereof.

FRANK MARTINDELL.

